Suspension of registration where return discrepancies threaten revenue; electronic intimation and mandatory online reply may lead to revocation or cancellation. Immediate suspension of registration applies where comparison of returns and supplier data reveals significant discrepancies threatening revenue, with electronic intimation of reasons and a requirement that the taxpayer explain why registration should not be cancelled within the prescribed reply period; taxpayers must respond online and the proper officer may revoke suspension or proceed to cancel registration after examining the response.